I don't think you can go wrong with either. Eamon is different and interesting, but would probably get mispronounced/ misspelled a lot. I don't see that as a big issue, but it depends on whether or not it bothers you. Ian has a more familiar feel, but I've only known 3 in my life: a Canadian archaeology professor, a Canadian student in China, and a coworker in the US. So although it's easily recognizable, it's not as common as one might think... I don't know any baby Ians, actually...

I don't think you can go wrong with either. Eamon is different and interesting, but would probably get mispronounced/ misspelled a lot. I don't see that as a big issue, but it depends on whether or not it bothers you.

Also keep in mind that even if it doesn't bother you, it might bother your son. Whenever anyone reads his name before he has a chance to introduce himself, they will get it wrong. And then, even if he tells them how to pronounce it, there's a good chance that they will continue to get it wrong. Over the years I've gotten used to people mispronouncing my name, but it can suck sometimes.